Leak-Preventing Device for a Pump

ABSTRACT

A pump includes a shell, an air-pumping device, a cover, a valve and a buoyant. The air-pumping device is used for pumping air out of the shell and therefore pumping liquid into the shell. The cover includes an opening and channel defined therein. The cover is attached to the shell and the air-pumping device. The shell is in communication with the exterior thereof via the opening. The shell is in communication with the air-pumping device via the channel. The valve is movable between a first position for releasing the channel and a second position for blocking the channel. The valve is in the second position as the pump is in an inverted position. The buoyant is used for moving the valve to the second position as the pump is almost full of liquid in an upright position.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a pump and, more particularly, to aleak-preventing device for a pump.

2. Related Prior Art

Referring to FIG. 1, a conventional pump 10 is located in an invertedposition. The pump 10 includes a shell 11 formed with an upper end 12and a lower end (not shown). The upper end 12 of the shell 11 is an openend. A check valve (not shown) is located in an aperture (not shown)defined in the lower end of the shell 11. A cylinder 14 is located inthe shell 11. A lower end of the cylinder 14 is attached to the lowerend of the shell 11. Thus, the space defined in the cylinder 14 isseparated from the space defined in the shell 11. The check valve islocated in the cylinder 14. A flexible piston (not shown) is located inand movable along the cylinder 14. The flexible piston is connected toan end of a rod while a handle is connected to an opposite end of therod. An annular buoyant 13 is located around and movable along thecylinder 14. A cover 20 is connected to the shell 11 and the cylinder14. The space defined in the shell 11 is in communication with the spacedefined in cylinder 14 through a channel 22 defined in the cover 20. Thecover 20 includes an opening 21 defined therein. A valve 18 is used toclose a first end of the channel 22 located in the space defined in theshell 11. A lever 17 is connected to the valve 18 at an end andconnected to another buoyant 16 at an opposite end. The pump is usefulin pumping liquid such as used oil 15 out of an oil pan of an engine offor example.

In use, the pump is located in an upright position. A plug (not shown)is fit in the opening 21. A flexible pipe (not shown) is insertedthrough the plug. An end of the flexible pipe is located in the spacedefined in the shell 11 while another end of the flexible pipe islocated in the used oil 15 contained in the oil pan. The flexible pistonis reciprocated in the cylinder 14 to pump air out of the space definedin the cylinder 14 and hence out of the space defined in the shell 11.Some of the used oil 15 is hence pumped from the oil pan into the spacedefined in the shell 11.

When the space defined in the shell 11 is almost full of the used oil15, the channel 22 is blocked by the valve 18 lifted by the buoyant 16and the annular buoyant 13 floating on the used oil 15 contained in thepump 10. Thus, the used oil 15 cannot be pumped into the space definedin the shell 11.

Referring to FIG. 2, to pour the used oil from the pump 10, the plug isremoved from the opening 21, and the pump 10 is tilted or even inverted.The used oil is supposed to leave the pump 10 through the opening 21only. However, there is inevitably leak of the used oil from the pump 10through the channel 22 because the channel 22 is released from the valve18 moved with the buoyant 16.

The present invention is therefore intended to obviate or at leastalleviate the problems encountered in prior art.

SUMMARY OF INVENTION

It is the primary objective of the present invention to provide a pumpthat can prevent leak.

To achieve the foregoing objective, the pump includes a shell, anair-pumping device, a cover, a valve and a buoyant. The air-pumpingdevice is used for pumping air out of the shell and therefore pumpingliquid into the shell. The cover includes an opening and channel definedtherein. The cover is attached to the shell and the air-pumping device.The shell is in communication with the exterior thereof via the opening.The shell is in communication with the air-pumping device via thechannel. The valve is movable between a first position for releasing thechannel and a second position for blocking the channel. The valve is inthe second position as the pump is in an inverted position. The buoyantis used for moving the valve to the second position as the pump isalmost full of liquid in an upright position.

Other objectives, advantages and features of the present invention willbe apparent from the following description referring to the attacheddrawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration ofseven embodiments versus the prior art referring to the drawingswherein:

FIG. 1 is a partial, cross-sectional view of a conventional pump in anupright position;

FIG. 2 is a partial, cross-sectional view of the conventional pump ofFIG. 1 in an inverted position;

FIG. 3 is a partial, cross-sectional view of a pump equipped with aleak-preventing device in accordance with the first embodiment of thepresent invention;

FIG. 4 is a partial, cross-sectional view of the pump in an invertedposition opposite to that is shown in FIG. 3;

FIG. 5 is a cross-sectional view of a pump equipped with aleak-preventing device in accordance with the second embodiment of thepresent invention;

FIG. 6 is a partial, cross-sectional view of the pump of FIG. 5 butshows the leak-preventing device in a second position;

FIG. 7 is an enlarged, cross-sectional view of the leak-preventingdevice shown in FIG. 6;

FIG. 8 is an enlarged, exploded view of the leak-preventing device shownin FIG. 7;

FIG. 9 is a partial, cross-sectional view of the pump in an invertedposition opposite to the upright position shown in FIG. 5 and shows theleak-preventing device in a second position;

FIG. 10 is a partial, cross-sectional view of a pump equipped with aleak-preventing device in accordance with the third embodiment of thepresent invention;

FIG. 11 is a partial, cross-sectional view of the pump in an invertedposition opposite to the upright position shown in FIG. 10;

FIG. 12 is a partial, cross-sectional view of a pump equipped with aleak-preventing device in accordance with the fourth embodiment of thepresent invention;

FIG. 13 is a partial, cross-sectional view of the pump in an invertedposition opposite to the upright position shown in FIG. 12;

FIG. 14 is a partial, cross-sectional view of a pump equipped with aleak-preventing device in accordance with the fifth embodiment of thepresent invention;

FIG. 15 is a partial, cross-sectional view of the pump in an invertedposition opposite to the upright position shown in FIG. 14;

FIG. 16 is a partial, cross-sectional view of a pump equipped with aleak-preventing device in accordance with the sixth embodiment of thepresent invention;

FIG. 17 is a partial, cross-sectional view of the pump in an invertedposition opposite to the upright position shown in FIG. 16;

FIG. 18 is a partial, cross-sectional view of a pump equipped with aleak-preventing device in accordance with the seventh embodiment of thepresent invention; and

FIG. 19 is a partial, cross-sectional view of the pump in an invertedposition opposite to the upright position shown in FIG. 18.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to FIGS. 3 and 4, an inverted-position leak-preventing devicein accordance with a first embodiment of the present invention is shown.The inverted-position leak-preventing device is used in the conventionalpump 10 discussed in the Related Prior Art with reference to FIGS. 1 and2. The inverted-position leak-preventing device includes a weight Amovably located in a pocket B intersecting the channel 22. The pocket Bis substantially located below the channel 22 as the pump 10 is theupright position shown in FIG. 3.

As shown in FIG. 3, the space defined in the shell 11 is almost full ofthe used oil 15, the channel 22 is blocked by the valve 18 lifted by thebuoyant 16 and the annular buoyant 13 floating on the used oil 15contained in the pump 10. Thus, the used oil 15 cannot be pumped intothe space defined in the shell 11.

As shown in FIG. 4, to pour the used oil from the pump 10, the plug isremoved from the opening 21, and the pump 10 is inverted so that theweight A falls and blocks the channel 22. Hence, the used oil leaves thepump 10 only through the opening 21. That is, there is no leak of theused oil from the pump 10 through the channel 22.

Referring to FIGS. 5 through 9, there is shown a pump 30 in accordancewith a second embodiment of the present invention. The pump 30 includesa shell 31, a cover 40, an air-pumping device and a leak-preventingdevice 60.

The shell 31 is formed with a lower end 32 and an upper end 35. Theshell 31 includes a base 33 formed at the lower end 32. A check valve 34is located in an opening (not shown) defined in the lower end 32 of theshell 31. The upper end 35 of the shell 31 is an open end.

The air-pumping device includes a cylinder 50, a handle 51, a rod 52 anda flexible piston 53. The cylinder 50 is located in the shell 31. Alower end of the cylinder 50 is attached to the lower end 32 of theshell 31 by welding for example. Thus, the space defined in the cylinder50 is separated from the space defined in the shell 31. The check valve34 is located in the cylinder 50. The flexible piston 53 is located inand movable along the cylinder 50. The rod 52 is connected to theflexible piston 53 at an end and connected to the handle 51 at anotherend.

The cover 40 includes a handle 41 formed thereon, an aperture definedtherein axially, an opening 42 defined therein longitudinally, a channel43 defined therein in a radial direction, an upper port defined thereinlongitudinally, and a lower port defined therein longitudinally. Thechannel 43 is in communication with the aperture at an end and incommunication with both of the upper and lower ports at an opposite end.The cover 40 is connected to the shell 31 and the cylinder 50 so thatthe space defined in the shell 31 is in communication with the spacedefined in the cylinder 50 through the channel 43. The rod 52 isinserted through the aperture. A relief valve 44 is located in the upperport.

The leak-preventing device 60 is used to close the second end of thechannel 43. As clearly shown in FIGS. 5 through 8, the leak-preventingdevice 60 includes a short tube 61, a ring 66, a long tube 80, a valve70 and a buoyant 71. The short tube 61 extends from a lower face of thecover 40 so that the short tube 61 includes a tunnel in communicationwith the channel 43. The tunnel defined in the short tube 61 includestwo sections 62 and 63. The diameter of the first section 62 is smallerthan that of the second section 63, thus forming an annular shoulder onan internal side of the short tube 61 between the sections 62 and 63.The short tube 61 further includes slots 64 in communication with thesecond section 63 of the tunnel of the short tube 61. There is a thread65 extending on an internal side of the short tube 61.

The ring 66 includes a cylindrical aperture 67 defined therein and afrusto-conical aperture 68 in communication with the cylindricalaperture 67. The cylindrical aperture 67 is made with a constantdiameter throughout its axis. The frusto-conical aperture 68 is madewith a diameter that decreases toward the cylindrical aperture 67. Thus,the cylindrical aperture 67 and the frusto-conical aperture 68 togetherdefine a tunnel that looks like an inverted funnel when the pump 30 islocated in the upright position. The ring 66 is fit in the secondsection 63 of the tunnel of the short tube 61 and abutted against theannular shoulder. Thus, the liquid is not allowed to go between the ring66 and the short tube 61. The tunnel defined in the ring 66 is incommunication with the tunnel defined in the short tube 61.

The valve 70 is in the form of a ball. The valve 70 is made of amaterial with a density larger than that of liquid to be pumped into thepump 30. That is, the valve 70 along does not float on the liquid.Preferably, the valve 70 is made of metal. The valve 70 is movablylocated in the second section 63 of the tunnel defined in the short tube61.

The buoyant 71 includes an upper section 72 and a lower section 73. Thediameter of upper section 72 is smaller than that of the lower section73. The upper section 72 of the buoyant 71 is movably inserted in thesecond section 63 of the tunnel defined in the short tube 61.

The long tube 80 includes a thread 81 extending on an internal side nearan open upper end thereof, an aperture 82 defined in a lower end, andslots 83 defined therein. The thread 81 is engaged with the thread 65,thus connecting the long tube 80 to the short tube 61. The buoyant 71 ismovably located in the long tube 80.

The pump 30 is useful in pumping liquid such as used oil out of an oilpan of an engine of for example. Referring to FIG. 5, in use, the pump30 is located in an upright position. The lower port defined in thecover 40 and hence the channel 43 is released from the valve 70. Asshown in a phantom line in FIG. 5, a plug is fit in the opening 42, anda flexible pipe C is inserted through the plug. An end of the flexiblepipe C is inserted in the space defined in the shell 31 while anotherend of the flexible pipe C is inserted in the used oil contained in theoil pan. By operating the handle 51, the flexible piston 53 isreciprocated in the cylinder 50 to pump air out of the space defined inthe cylinder 50 and hence out of the space defined in the shell 31,i.e., vacuum is created in the space defined in the shell 31. Therefore,some of the used oil is pumped from the oil pan into the space definedin the shell 31.

Referring to FIG. 6, as the space defined in the shell 31 is almost fullof the used oil, the lower port defined in the cover 40 and hence thechannel 43 is blocked by the valve 70 lifted by the buoyant 71 floatingon the used oil contained in the space defined in the shell 31. Thus, nomore air can be pumped out of the space defined in the cylinder 50 andhence out of the space defined in the shell 31. Therefore, no more usedoil can be pumped from the oil pan into the space defined in the shell31 by operating the handle 51.

Referring to FIG. 9, to pour the used oil from the pump 30, the plug isremoved from the opening 42, and the pump 30 is tilted or inverted. Thefirst section 62 of the first pipe 61 is closed by the valve 70 thatsinks into the used oil. Accordingly, the channel 43 is closed. Hence,the used oil leaves the pump 30 through the opening 42 only. There is noleak of the used oil from the pump 30 through the channel 43.

Referring to FIGS. 10 and 11, there is shown a leak-preventing device 60in accordance with a third embodiment of the present invention. Thethird embodiment is like the second embodiment except several things. Atfirst, there is formed a short tube 62 a instead of the short tube 61.The short tube 62 a extends much shorter than the short tube 61.Moreover, the tunnel defined in the short tube 62 a is made with aconstant internal diameter. Secondly, there is used a valve 70 a insteadof the valve 70. The valve 70 a is in the form of a piston. Thirdly, thering 66 is omitted. Fourthly, there is used a buoyant 71 a instead ofthe buoyant 71. The buoyant 71 a is in the form of a cylinder with aconstant external diameter.

Referring to FIGS. 12 and 13, there is shown a leak-preventing device 60in accordance with a fourth embodiment of the present invention. Thefourth embodiment is like the third embodiment except several things. Atfirst, there is used a valve 70 b instead of the valve 70 a. The valve70 b includes a first section 74 and a second section 75 made with adiameter smaller than that of the first section 74. The first section 74of the valve 70 b is used for contact with the short tube 62 a. Thesecond section 75 of the valve 70 b is inserted through the aperture 82.Secondly, there is used an annular buoyant 13 instead of the buoyant 71a. The annular buoyant 13 is located around and movable along thecylinder 50 as in the first embodiment.

Referring to FIGS. 14 and 15, there is shown a leak-preventing device 60in accordance with a fifth embodiment of the present invention. Thefifth embodiment is like the fourth embodiment except including a valve70 c instead of the valve 70 b. The valve 70 c is identical to the valve70 b except including a boss 76 extending from the first section 74thereof. The boss 76 can be inserted in the short tube 62 a.

Referring to FIGS. 16 and 17, there is shown a leak-preventing device 60in accordance with a sixth embodiment of the present invention. Thesixth embodiment is like the fifth embodiment except two things. Atfirst, there is used a valve 70 d instead of the valve 70 c. The valve70 d is identical to the valve 70 c except including a recess 77 definedin the first section 74 thereof. Secondly, there is a solid ball 78located in recess 77. The solid ball 78 can be inserted in the shorttube 62 a.

Referring to FIGS. 18 and 19, there is shown a leak-preventing device 60in accordance with a seventh embodiment of the present invention. Theseventh embodiment is like the sixth embodiment except including ahollow ball 79 instead of the solid ball 78.

The present invention has been described via the detailed illustrationof the embodiments. Those skilled in the art can derive variations fromthe embodiments without departing from the scope of the presentinvention. Therefore, the embodiments shall not limit the scope of thepresent invention defined in the claims.

1. A pump including: a shell; an air-pumping device for pumping air outof the shell, thus pumping liquid into the shell; a cover including anopening and channel defined therein, wherein the shell is incommunication with the exterior thereof via the opening and incommunication with the air-pumping device via the channel as the coveris attached to the shell and the air-pumping device; a valve movable inthe shell between a first position for releasing the channel and asecond position for blocking the channel, wherein the valve is in thesecond position as the pump is in an inverted position; and a buoyantfor moving the valve to the second position as the pump is almost fullof liquid in an upright position.
 2. The pump in accordance with claim1, further including a long tube connected to the cover and formed witha tunnel in communication with the tunnel defined in the cover, whereinthe valve is movably located in the long tube.
 3. The pump in accordancewith claim 2, wherein the buoyant is movably located in the long tube.4. The pump in accordance with claim 2, wherein the buoyant is movablylocated outside the long tube.
 5. The pump in accordance with claim 4,wherein the valve includes a first end movably located in the long tubeand a second end movably located outside the long tube.
 6. The pump inaccordance with claim 2, further including a short tube extending fromthe cover and including a tunnel in communication with the channeldefined in the cover, wherein the long tube is connected to the shorttube.
 7. The pump in accordance with claim 6, wherein the short tubeincludes a thread extending on an external side thereof, wherein thelong tube includes a thread extending on an internal side thereof forengagement with the thread of the short tube.
 8. The pump in accordancewith claim 1, furthering including a ring fit in the long tube and usedfor contact with the valve.
 9. The pump in accordance with claim 6,wherein the ring includes a frusto-conical aperture defined therein,wherein the valve is a ball for firm contact with an internal side ofthe ring.
 10. The pump in accordance with claim 1, wherein the valve isa ball.
 11. The pump in accordance with claim 1, wherein the valve isformed with a boss for blocking the tunnel defined in the cover.
 12. Thepump in accordance with claim 1, further including a ball in contactwith the valve.
 13. The pump in accordance with claim 12, wherein theball is solid.
 14. The pump in accordance with claim 12, wherein theball is hollow.
 15. The pump in accordance with claim 12, wherein thevalve includes a recess defined therein for receiving the ball.
 16. Thepump in accordance with claim 1, wherein the air-pumping device includesa cylinder located in and connected to the shell, a flexible pistonmovable in the cylinder, a rod connected to the flexible piston, ahandle connected to the rod, and a check valve attached to an end of thecylinder.
 17. A pump including: a shell; an air-pumping device forpumping air out of the shell and therefore pumping liquid into theshell; a cover including an opening and a channel defined therein,wherein the shell is in communication with the exterior thereof via theopening and in communication with the air-pumping device via the channelas the cover is attached to the shell and the air-pumping device; afirst valve movable in the shell between a first position for releasingthe channel and a second position for blocking the channel; a buoyantfor floating on liquid pumped into the pump and moving the first valveto the second position as the pump is almost full of the liquid in anupright position; and a second valve A movable in the shell between afirst position for releasing the channel as the pump is in the uprightposition and a second position for blocking the channel as the pump isin an inverted position.
 18. The pump in accordance with claim 17,wherein the cover includes a pocket B that intersects the channel,wherein the second valve A is movably located in the pocket B.